Multiple Sites Research Articles

Preparation of a bis-triazolyl bridged β-cyclodextrin stationary phase and its application for enantioseparation of chiral compounds by HPLC.

A novel bis-triazolyl bridged β-cyclodextrin was first synthesized by the Click reaction between azido-β-cyclodextrin and 1,6-heptadiyne. Then it was bonded onto silica gel to obtain a bis-triazolyl bridged β-cyclodextrin-based chiral stationary phase (BCDP). After structure characterization, the HPLC performance of BCDP was systematically evaluated by using different types of compounds as probes. The results showed that BCDP could well separate 18 kinds of achiral aromatic compounds (homologues, positional isomers, etc.) and 35 kinds of chiral drugs or pesticides, such as triazoles (Rs = 1.33-3.15), flavanones (Rs = 1.49-2.62), dansyl amino acids (Rs = 0.96-1.99), and β-blocker drugs (Rs = 0.68-2.78). BCDP could separate a wider range of compounds (53 kinds); especially, some chiral substance pairs that were difficult to be resolved on the ordinary cyclodextrin CSPs, including triazoles containing two chiral carbons (triadimenol, bitertanol, metconazole, and triticonazole), strongly ionized amino acids (acidic Asp, alkalic Arg, and polar Thr) and β-blockers with bulky groups (carvedilol, propranolol, and pindolol). Obviously, the unique synergistic inclusion effect of bridged cyclodextrin with double cavities and the bis-triazole bridging group could provide multiple action sites, such as hydrogen bonding, π-π stacking and acid-base action sites, thus improving its chiral chromatographic performance.

Longitudinal Analysis of Mpox Virus DNA Detectability From Multiple Specimen Types During Acute Illness: A Cohort Study.

Longitudinal data on the detectability of monkeypox virus (MPXV) genetic material in different specimen types are scarce. We describe MPXV-specific polymerase chain reaction (PCR) results from adults with confirmed mpox infection from Toronto, Canada, including a cohort undergoing weekly collection of specimens from multiple anatomic sites until 1 week after skin lesions had fully healed. We quantified the time from symptom onset to resolution of detectable viral DNA (computed tomography [Ct] ≥ 35) by modeling exponential decay in Ct value as a function of illness day for each site, censoring at the time of tecovirimat initiation. Among 64 men who have sex with men, the median (interquartile range [IQR]) age was 39 (32.75-45.25) years, and 49% had HIV. Twenty received tecovirimat. Viral DNA was detectable (Ct < 35) at baseline in 74% of genital/buttock/perianal skin swabs, 56% of other skin swabs, 44% of rectal swabs, 37% of throat swabs, 27% of urine, 26% of nasopharyngeal swabs, and 8% of semen samples. The median time to resolution of detectable DNA (IQR) was longest for genital/buttock/perianal skin and other skin swabs at 30.0 (23.0-47.9) and 22.4 (16.6-29.4) days, respectively, and shortest for nasopharyngeal swabs and semen at 0 (0-12.1) and 0 (0-0) days, respectively. We did not observe an effect of tecovirimat on the rate of decay in viral DNA detectability in any specimen type (all P > .05). MPXV DNA detectability varies by specimen type and persists for over 3-4 weeks in skin specimens. The rate of decay did not differ by tecovirimat use in this nonrandomized study.

New materials-based on gelatin coordinated with zirconium or aluminum for ecological retanning

Ecological retanning agent is an effective way to solve the pollution source of leather manufacturing industry. In this study, the gelatin from chrome-containing leather shavings in the leather industry was used to realize sustainable leather post-tanning. The gelatin hydrolysate (GH) coordinated with Zr4+ or Al3+ to prepare eco-friendly retanning agents GH-Zr and GH-Al. The successful coordination between GH and metal ions was characterized by FTIR and XPS. The retanning agents were characterized by FTIR curve-fitting and circular dichroism spectroscopy. The results showed that the conformation of the secondary structure of the polypeptide became ordered and stable after coordinating with the metal ions. The particle size and weight average molecular weight of the retanning agents were ~1700 nm and ~2100, respectively, measured by nanoparticle size analyzer and gel permeation chromatography (GPC). The retanning agents were applied to retanning of chrome tanned leather and glutaraldehyde tanned leather. The abundant free amino from retanning agents can consume the free formaldehyde. Meanwhile, retanning agents can effectively improve the multiple binding sites, resulting in favorable thickening rate (>110 %) and excellent dye and fatliquor absorption rate with ~99.91 % and ~93.18 %. Thus, this strategy can provide a viable choice for solid leather waste and sustainable development of the leather industry.

Abstract TMP81: Effect of Post Thrombolytic Intracerebral Hemorrhage Volume on 90-day Outcomes in Acute Ischemic Stroke Patients

Background and Purpose: Post thrombolytic intracerebral hemorrhage (ICH) is associated with higher rate of death or disability in acute ischemic stroke patients. We investigated the relationship between post thrombolytic ICH volume and change in volume and death or disability at 90 days in acute ischemic stroke patients. Methods: We analyzed 110 patents recruited in the Safety Evaluation of 3K3A-APC in Ischemic Stroke (RHAPSODY) trial who received intravenous tissue plasminogen activator (tPA) followed by mechanical thrombectomy (if indicated) and 3K3A-APC or placebo. ICH volume was measured at Day 2 and Day 7 using susceptibility weighted sequence (SWI) on magnetic resonance imaging (MRI). We also calculated the post thrombolytic ICH volume change between Day 2 and Day 7. Outcomes were determined by using utility weighted modified Rankin scale (UW-mRs) at 90-days. We adjusted for age, gender, National Institute of Health Stroke Scale (NIHSS) score (&lt;10,10-19 and ≥20), location of hemorrhage (single basal ganglia hemorrhage, single lobar, single cerebellum, and multiple sites hemorrhage) in multivariate regression analysis. Results: A total of 88 (80%) of 110 patients had post thrombolytic ICH (mean volume 28.3 ml ± SD 62ml). The strata of ICH volume were not associated with UW-mRs at 90 days: &lt;20 cc (regression coefficient-0.05, p= 0.58), 20-39 cc (-0.23, p=0.15), or 40 cc (-0.33, p= 0.086) compared with no ICH after adjusting for potential confounders. Change in ICH volume mean volume 27.43ml ±59.01, 52 had increase in volume) between Day 2 and day 7 was not associated with UW-mRS at 90 days (regression coefficient -11.87, p= 0.796). Conclusions: We did not observe any independent effect of post thrombolytic ICH volume on death or disability in acute ischemic stroke patients. Strategies to prevent ICH expansion such as antifibrinolytic medications and reduction in ICH volume such as surgical evacuation may not reduce death or disability in acute ischemic stroke patients with post thrombolytic ICH.

Abstract TP43: Optimizing System-Wide Nursing Assessment Documentation in the Stroke Population

Background: Stroke centers following AHA guidelines for the treatment of acute ischemic stroke, are challenged by compliance with documentation of vital sign, neuro and neurovascular assessments post thrombolysis interventions. Standardizing documentation in the electronic health record (EHR) increases compliance and reduces patient harm. In a large healthcare system, multiple sites received corrective action findings from regulatory agencies for missed nursing assessments. The centers did not have a documentation workflow aligned with the EHR to capture assessments in the stroke population. Purpose: To create a system-wide documentation workflow that captures nursing assessments in the EHR. Methods: In 2019 a task force of stroke coordinators and clinical informaticists convened to define evidence-based nursing assessments in stroke patients post intervention, define within normal limits for each component, and identify barriers to documentation in the EHR. The EHR was evaluated for component location and other areas in need of optimization. Components were scattered across different EHR locations, leading to missing documentation and assessments were difficult to trend. The task force led the development and implementation of a single EHR location to document nursing assessments. The EHR revisions were implemented in July 2022 after being vetted by system EHR governance, nurse practice council, and stroke coordinator collaborative. Results: A single grouping was developed in the EHR including vitals, focused neurological and neurovascular assessments. This grouping was strategically placed within nursing’s existing workflow. Reference text addressing each element of the grouping and its “within defined limits’ definition were added to align with the organization's documentation standards. To increase visibility of documentation, trending, and the auditing process, a single results view was developed which included all documented assessment components. Conclusion: A system-wide documentation workflow aligned with the EHR optimized documentation workflow, improved visibility of assessments, reduced audit time and regulatory findings. Stroke centers should carefully consider the layout of nursing documentation in the EHR.

Enoxaparin-induced cutaneous panniculitis in a pregnant female

Low-molecular-weight heparins (LMWHs) are currently used as an antithrombotic prophylactic therapy during pregnancy and in post-surgery patients. The safety of various drugs in pregnancy has always been a matter of concern. Enoxaparin, being associated with low fetal and neonatal complications, is used extensively to improve the outcomes in high-risk pregnancies. The duration of treatment with LMWH in pregnancy is generally long; hence, strict monitoring of side effects should be done. We report a case of a 25-year-old pregnant female who experienced painful, erythematous skin necrosis and panniculitis after prophylactic administration of enoxaparin at multiple sites subcutaneously.

Radiologic patterns of distant organ metastasis in advanced breast cancer patients: Prospective review of computed tomography images.

Breast cancer (BC) metastases to the abdomen and pelvis affect the liver, mesentery, retroperitoneum, peritoneum, bladder, kidney, ovary, and uterus. The study documented the radiological pattern and features of the chest, bone, abdominal and pelvic (AP) metastases among advanced BC patients. The aim is to document the radiological pattern and features of breast cancer metastasis in the chest, abdomen, pelvis and bones. Chest, abdominal, and pelvic computed tomography scan images of 36 patients with advanced BC were collated from Cape Coast Teaching Hospital and RAAJ Diagnostics. The images were prospectively assessed for metastasis to the organs of the chest, AP soft tissues, and bones. Radiologic features of metastasis of the lungs, liver, lymph nodes (LNs), and bones were documented. Patients' demographics, clinical data, and histopathology reports were also collected. The data were captured using UVOSYO and exported to Microsoft Excel templates. The data obtained were descriptively analyzed. Only 2.8% of BCs exhibited metaplastic BC, whereas 97.2% had invasive ductal BC. Triple-negative cases were 55.6%. Of 36 patients, 31 (86.1%), 21 (58.3%), and 14(38.8%) were diagnosed of chest, AP, and bone tissues metastasis, respectively. LN involvement was reported in 26 (72.2%) patients. Majority, 21 (58.3%) were diagnosed of multiple sites metastasis with 15 (41.7%) showing single site. Lungs (77.4%, 24/31) and liver (47.6%, 10/21) were the most affected distant organs. Most bone metastases were lytic lesions (92.9%, 13/14) with the vertebrae (85.7%, 12/14) been the most affected. According to the study, advanced BC patients have a higher-than-average radiologic incidence of lung, liver, bone, and LN metastases.

Cell surface architecture of the cultivated DPANN archaeon Nanobdella aerobiophila.

The DPANN archaeal clade includes obligately ectosymbiotic species. Their cell surfaces potentially play an important role in the symbiotic interaction between the ectosymbionts and their hosts. However, little is known about the mechanism of ectosymbiosis. Here, we show cell surface structures of the cultivated DPANN archaeon Nanobdella aerobiophila strain MJ1T and its host Metallosphaera sedula strain MJ1HA, using a variety of electron microscopy techniques, i.e., negative-staining transmission electron microscopy, quick-freeze deep-etch TEM, and 3D electron tomography. The thickness, unit size, and lattice symmetry of the S-layer of strain MJ1T were different from those of the host archaeon strain MJ1HA. Genomic and transcriptomic analyses highlighted the most highly expressed MJ1T gene for a putative S-layer protein with multiple glycosylation sites and immunoglobulin-like folds, which has no sequence homology to known S-layer proteins. In addition, genes for putative pectin lyase- or lectin-like extracellular proteins, which are potentially involved in symbiotic interaction, were found in the MJ1T genome based on in silico 3D protein structure prediction. Live cell imaging at the optimum growth temperature of 65°C indicated that cell complexes of strains MJ1T and MJ1HA were motile, but sole MJ1T cells were not. Taken together, we propose a model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila.IMPORTANCEDPANN archaea are widely distributed in a variety of natural and artificial environments and may play a considerable role in the microbial ecosystem. All of the cultivated DPANN archaea so far need host organisms for their growth, i.e., obligately ectosymbiotic. However, the mechanism of the ectosymbiosis by DPANN archaea is largely unknown. To this end, we performed a comprehensive analysis of the cultivated DPANN archaeon, Nanobdella aerobiophila, using electron microscopy, live cell imaging, transcriptomics, and genomics, including 3D protein structure prediction. Based on the results, we propose a reasonable model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila, which will enhance our understanding of the enigmatic physiology and ecological significance of DPANN archaea.

Electropolymerization stabilized bipolar metal coordination complex for high-performance dual-ion batteries

Metal coordination complexes with remarkable redox activity and high working voltage are plagued by their limited specific capacity and sever dissolution problem. A bipolar cobalt-based coordination polymer (CoL) bearing both p-type and n-type active centers was synthesized via the in-situ electropolymerization method with collective merits of multiple redox sites, dual-ion storage capability, and excellent chemical stability. As-prepared electrodes delivered remarkable performances including a high discharge specific capacity of 192.13 mAh/g (at 0.05 A/g), stable cycling over 2000 cycles with 89% capacity retention (at 5A/g), and excellent rate capability. Moreover, the dual-ion storage processes were unveiled by ex-situ Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis. It provides insight to design and synthesis of electropolymerized bipolar electrode for high performance dual-ion batteries.

One-year surveillance for hypervirulent Klebsiella pneumoniae detected carbapenem-resistant superbugs.

Hypervirulent Klebsiella pneumoniae (hvKp) can cause infections in clinically healthy people, such as young and immunocompetent patients. Genes involved in the capsule synthesis or those encoding the siderophores have been adopted as predictors of hvKp. Certain sequence types, such as ST23 and ST86, have been associated with hvKp strains, too. The aim of this study was to investigate the presence of hvKp among 354 K. pneumoniae strains isolated from clinical samples of patients admitted to an Italian 900-bed hospital between 21 May 2021 and April 2022. All the isolates were screened by PCR for the amplification of virulence loci. Whole genome sequencing was performed in strains tested positive for at least one target gene. Thirteen out of 354 (3.7%) were hvKp. Five were wild type and belonged to the hypervirulent clones ST23, ST86, ST5, and ST375 and to the new clone ST6310. Six strains carried the blaKPC gene: three belonged to ST101, two to ST512, and one to ST395. Two isolates were ST147 and carried the blaNDM gene. Although hvKp isolation is not frequent, their presence should be systematically investigated to avoid the spreading of both virulent strains and strains with combined increase in virulence and resistance to antibiotics. PCR-based protocols are essential for surveillance of these strains, which do not always show a recognizable phenotype. Moreover, hvKp strains were isolated also from patients without history of recent foreign travels, indicating an increased spreading of these strains as well as an underestimated of their circulation so far.IMPORTANCEKlebsiella pneumoniae is a healthcare-associated pathogen frequently resistant to antibiotics. Hypervirulent strains of pneumoniae (hvKp) can spread from the primary site of infection to multiple sites causing life-threatening infections also in young otherwise healthy individuals. This study described the isolation of 13 isolates of K. pneumoniae with increased virulence in a large tertiary hospital over a 1-year period. Among them, eight strains were multidrug resistant and hypervirulent. Although these hypervirulent strains are still rare in Italy, their presence is particularly concerning since they can cause difficult-to-treat life-threatening infections. Moreover, not all the hypervirulent isolates were positive by the string test, so hvKp isolates were not always phenotypically detectable. Molecular biology techniques such as PCR amplification and next generation sequencing are therefore necessary for the detection of hvKp isolates, and surveillance programs exploiting molecular techniques are highly desirable.

Microporous Fluorinated MOF with Multiple Adsorption Sites for Efficient Recovery of C2H6 and C3H8 from Natural Gas.

Purifying C2H6/C3H8 from a ternary natural gas mixture through adsorption separation is an important but challenging process in the petrochemical industry. To address this challenge, the industry is exploring effective strategies for designing high-performance adsorbents. In this study, we present two metal-organic frameworks (MOFs), DMOF-TF and DMOF-(CF3)2, which have fluorinated pores obtained by substituting linker ligands in the host material. This pore engineering strategy not only provides suitable pore confinement but also enhances the adsorption capacities for C2H6/C3H8 by providing additional binding sites. Theoretical calculations and transient breakthrough experiments show that the introduction of F atoms not only improves the efficiency of natural gas separation but also provides multiple adsorption sites for C2H6/C3H8-framework interactions.

Production and secretion of recombinant spider silk in Bacillus megaterium

BackgroundSilk proteins have emerged as versatile biomaterials with unique chemical and physical properties, making them appealing for various applications. Among them, spider silk, known for its exceptional mechanical strength, has attracted considerable attention. Recombinant production of spider silk represents the most promising route towards its scaled production; however, challenges persist within the upstream optimization of host organisms, including toxicity and low yields. The high cost of downstream cell lysis and protein purification is an additional barrier preventing the widespread production and use of spider silk proteins. Gram-positive bacteria represent an attractive, but underexplored, microbial chassis that may enable a reduction in the cost and difficulty of recombinant silk production through attributes that include, superior secretory capabilities, frequent GRAS status, and previously established use in industry.ResultsIn this study, we explore the potential of gram-positive hosts by engineering the first production and secretion of recombinant spider silk in the Bacillus genus. Using an industrially relevant B. megaterium host, it was found that the Sec secretion pathway enables secretory production of silk, however, the choice of signal sequence plays a vital role in successful secretion. Attempts at increasing secreted titers revealed that multiple translation initiation sites in tandem do not significantly impact silk production levels, contrary to previous findings for other gram-positive hosts and recombinant proteins. Notwithstanding, targeted amino acid supplementation in minimal media was found to increase production by 135% relative to both rich media and unaltered minimal media, yielding secretory titers of approximately 100 mg/L in flask cultures.ConclusionIt is hypothesized that the supplementation strategy addressed metabolic bottlenecks, specifically depletion of ATP and NADPH within the central metabolism, that were previously observed for an E. coli host producing the same recombinant silk construct. Furthermore, this study supports the hypothesis that secretion mitigates the toxicity of the produced silk protein on the host organism and enhances host performance in glucose-based minimal media. While promising, future research is warranted to understand metabolic changes more precisely in the Bacillus host system in response to silk production, optimize signal sequences and promoter strengths, investigate the mechanisms behind the effect of tandem translation initiation sites, and evaluate the performance of this system within a bioreactor.

Blueshift and Photoluminescence Enhancement in Broadband Near‐Infrared Emitting Phosphor NaSr2(Al/Ga)Ge5O14: Cr3+ Dependence on the Sc/In Substitution

AbstractCr3+‐activated near‐infrared (NIR) phosphors have gained extensive attention for use in NIR phosphor‐converted light‐emitting diodes (pc‐LEDs), which are required for smart NIR spectroscopy techniques. Nevertheless, obtaining broadband NIR‐emitting phosphors with outstanding thermal stabilities and photoluminescence (PL) efficiencies remains a significant challenge. Herein, considering NaSr2XGe5O14 (X = Al, Ga, Sc, and In) as hosts, which possess a large band gap and multiple sites for the substitution of Cr3+ ions. NaSr2XGe5O14:Cr3+ phosphors are successfully prepared using a solid‐state reaction technology. Upon blue light excitation, the phosphors cover a broad NIR emission band in 650–1100 nm region. Notably, an abnormal blueshift and PL enhancement are observed following the substitution of Al/Ga with Sc/In. In particular, the PL internal quantum efficiency is improved from 34.5% (NaSr2GaGe5O14: Cr3+) to 87.5% (NaSr2ScGe5O14: Cr3+). Moreover, the manufactured NIR pc‐LED exhibited an exceptional photoelectric efficiency of 17.7% with an NIR output power of 10.2 mW at 20 mA, and its potential application in nondestructive detection is demonstrated.

Proline-directed yeast and human MAP kinases phosphorylate the Dot1p/DOT1L histone H3K79 methyltransferase.

Disruptor of telomeric silencing 1 (Dot1p) is an exquisitely conserved histone methyltransferase and is the sole enzyme responsible for H3K79 methylation in the budding yeast Saccharomyces cerevisiae. It has been shown to be highly phosphorylated in vivo; however, the upstream kinases that act on Dot1p are almost entirely unknown in yeast and all other eukaryotes. Here, we used in vitro and in vivo kinase discovery approaches to show that mitogen-activated protein kinase HOG1 (Hog1p) is a bona fide kinase of the Dot1p methyltransferase. In vitro kinase assays showed that Hog1p phosphorylates Dot1p at multiple sites, including at several proline-adjacent sites that are consistent with known Hog1p substrate preferences. The activity of Hog1p was specifically enhanced at these proline-adjacent sites on Dot1p upon Hog1p activation by the osmostress-responsive MAP kinase kinase PBS2 (Pbs2p). Genomic deletion of HOG1 reduced phosphorylation at specific sites on Dot1p in vivo, providing further evidence for Hog1p kinase activity on Dot1p in budding yeast cells. Phenotypic analysis of knockout and phosphosite mutant yeast strains revealed the importance of Hog1p-catalysed phosphorylation of Dot1p for cellular responses to ultraviolet-induced DNA damage. In mammalian systems, this kinase-substrate relationship was found to be conserved: human DOT1L (the ortholog of yeast Dot1p) can be phosphorylated by the proline-directed kinase p38β (also known as MAPK11; the ortholog of yeast Hog1p) at multiple sites in vitro. Taken together, our findings establish Hog1p and p38β as newly identified upstream kinases of the Dot1p/DOT1L H3K79 methyltransferase enzymes in eukaryotes.

A Genome-Wide Association Study of Respiratory Syncytial Virus Infection Severity in Infants.

Respiratory syncytial virus (RSV) is a significant cause of infant morbidity and mortality worldwide. Most children experience at least one 1 RSV infection by the age of two 2 years, but not all develop severe disease. However, the understanding of genetic risk factors for severe RSV is incomplete. Consequently, we conducted a genome-wide association study of RSV severity. Disease severity was assessed by the ReSVinet scale, in a cohort of 251 infants aged 1 week to 1 year. Genotyping data were collected from multiple European study sites as part of the RESCEU Consortium. Linear regression models were used to assess the impact of genotype on RSV severity and gene expression as measured by microarray. While no SNPs reached the genome-wide statistical significance threshold (P < 5 × 10-8), we identified 816 candidate SNPs with a P-value of <1 × 10-4. Functional annotation of candidate SNPs highlighted genes relevant to neutrophil trafficking and cytoskeletal functions, including LSP1 and RAB27A. Moreover, SNPs within the RAB27A locus significantly altered gene expression (false discovery rate, FDR P < .05). These findings may provide insights into genetic mechanisms driving severe RSV infection, offering biologically relevant information for future investigations.

The CogniAid trial. The impact of two hearing aid signal processing strategies on cognition

BackgroundUntreated hearing loss is a risk factor for age-related cognitive decline and hearing aids have been shown to slow cognitive decline in a population at risk for dementia. This double-blind multiple site randomized trial tested the hypothesis that for older adults with below-average cognition, a “Simple” hearing aid fitting strategy (based on linear amplification with output limiting compression signal processing) would improve hearing and cognition more than a “Standard” approach (adaptive compression-based processing).MethodsTwo hundred and fifty-six adults aged over 65 were screened for cognitive function using the NIH toolbox cognitive battery. Participants with below median age-adjusted fluid composite cognitive scores (&amp;lt;100) were eligible to participate (n = 104). Sixty-seven eligible participants proceeded to trial and were randomized 1:1 to a simple or standard hearing aid fitting. Participants in the Standard group were fitted with hearing aids matched to non-linear real-ear prescription targets (either NAL-NL1 or NL2), while participants in the Simple group were fitted with hearing aids matched to linear prescription targets (NAL-R). Participants and researchers not fitting the hearing aids were blinded to allocation.ResultsForty-eight participants completed assessments in 12 months. The Standard hearing aid group improved on measures of fluid cognition and hearing. There was a statistically significant difference in fluid cognition scores between groups. The fluid cognition composite score for participants receiving the Simple fitting changed by 3.5 points. Those with the Standard fitting improved by 10.3 points. Hearing outcomes for each group were improved by the same amount.ConclusionThis is the first study to show that hearing aid fitting strategies using markedly different signal processing result in significantly different cognitive outcomes after 12 months of use. The Standard fitting resulted in greater improvement in cognition than the Simpler fitting which was the opposite result to what had been hypothesized. The results reinforce findings indicating hearing aid benefits for the elderly and that they improve cognition.

Determination of the Cannabinoid CB1 Receptor's Positive Allosteric Modulator Binding Site through Mutagenesis Studies.

Positive allosteric modulators (PAMs) of the cannabinoid CB1 receptor (CB1) offer potential therapeutic advantages in the treatment of neuropathic pain and addiction by avoiding the adverse effects associated with orthosteric CB1 activation. Here, molecular modeling and mutagenesis were used to identify residues central to PAM activity at CB1. Six putative allosteric binding sites were identified in silico, including novel sites previously associated with cholesterol binding, and key residues within each site were mutated to alanine. The recently determined ZCZ011 binding site was found to be essential for allosteric agonism, as GAT228, GAT229 and ZCZ011 all increased wild-type G protein dissociation in the absence of an orthosteric ligand; activity that was abolished in mutants F191A3.27 and I169A2.56. PAM activity was demonstrated for ZCZ011 in the presence of the orthosteric ligand CP55940, which was only abolished in I169A2.56. In contrast, the PAM activity of GAT229 was reduced for mutants R220A3.56, L404A8.50, F191A3.27 and I169A2.56. This indicates that allosteric modulation may represent the net effect of binding at multiple sites, and that allosteric agonism is likely to be mediated via the ZCZ011 site. This study underlines the need for detailed understanding of ligand receptor interactions in the search for pure CB1 allosteric modulators.

P1025 Analysis of the Clinical Characteristics of Elderly-onset Crohn's Disease

Abstract Background The prevalence of Crohn's disease in the elderly is increasing today. The purpose of this study was to analyze the clinical characteristics of elderly-onset patients with Crohn's disease and compare with non-elderly-onset adult patients. Methods All Crohn's disease patients with onset aged 60 years and older at our Inflammatory Bowel Disease Center in recently ten years were retrospectively included. The elderly were compared with adult patients aged 18-59 at the time of onset, who were matched according to diagnosis time and gender by a 1:3 ratio of propensity score matching. After matching, the clinical data were recorded and analyzed to compared between the two groups of patients. Results A total of 68 patients were included, including 17 patients in the elderly-onset group and 51 patients in the non-elderly-onset adult group. The mean age of diagnosis in the two groups was 30.3±8.7 years and 63.9±4.24 years, and the mean course of disease was 30.3 months and 63.9 months, respectively. According to the Montreal classification, most elderly patients presented with L3 (70.6%) and B1 (58.8%), no cases involving the upper digestive tract or multiple lesion sites, showed mild disease activity (76.5%). The elderly group had fewer intestinal complications and parenteral manifestations. The medication types of elderly are 5-aminosalicylates (52.9%), traditional immunosuppressive agents (45.6%) and enteral nutrition preparations (29.4%) being the more frequent types of medications used, and glucocorticoids and biologics being used less frequently. Exposure to two or more IBD medications was 31.4% and 52.9% in the non-elderly onset adult group versus the elderly onset group, respectively (p=0.110). During follow-up, symptoms such as diarrhea (11.8 vs 5.9%), abdominal pain (35.3% vs 17.6%) and weight loss (11.8% vs 3.9%) were more common in the elderly-onset group. Elderly patients had more hospitalizations on average (0.22 vs. 1.12). 40.7% of elderly patients underwent CD-related surgery during the duration of their disease, with 50.0% of patients undergoing reoperation. Conclusion Compared with non-elderly-onset adult patients, elderly-onset patients with Crohn's disease are more common in women, and the lesion mainly in the ileum and ilecolon; the disease behavior is mainly B1; nearly half of the patients have intestinal complications The elderly have atypical clinical manifestations, basically haven’t family history of IBD, take longer to diagnose, have more underlying diseases, more hospitalizations on average, and are more likely to have complications. They are more likely to receive conservative treatment, but with more frequent medication adjustments and a higher likelihood of undergoing CD-related surgery.

Intrinsically Disordered Regions in the Transcription Factor MYC:MAX Modulate DNA Binding via Intramolecular Interactions.

The basic helix-loop-helix leucine zipper (bHLH-LZ) transcription factor (TF) MYC is in large part an intrinsically disordered oncoprotein. In complex with its obligate heterodimerization partner MAX, MYC preferentially binds E-Box DNA sequences (CANNTG). At promoters containing these sequence motifs, MYC controls fundamental cellular processes such as cell cycle progression, metabolism, and apoptosis. A vast network of proteins in turn regulates MYC function via intermolecular interactions. In this work, we establish another layer of MYC regulation by intramolecular interactions. We used nuclear magnetic resonance (NMR) spectroscopy to identify and map multiple binding sites for the C-terminal MYC:MAX DNA-binding domain (DBD) on the intrinsically disordered regions (IDRs) in the MYC N-terminus. We find that these binding events in trans are driven by electrostatic attraction, that they have distinct affinities, and that they are competitive with DNA binding. Thereby, we observe the strongest effects for the N-terminal MYC box 0 (Mb0), a conserved motif involved in MYC transactivation and target gene induction. We prepared recombinant full-length MYC:MAX complex and demonstrate that the interactions identified in this work are also relevant in cis, i.e., as intramolecular interactions. These findings are supported by surface plasmon resonance (SPR) experiments, which revealed that intramolecular IDR:DBD interactions in MYC decelerate the association of MYC:MAX complexes to DNA. Our work offers new insights into how bHLH-LZ TFs are regulated by intramolecular interactions, which open up new possibilities for drug discovery.

Construction synergetic adsorption and activation surface via confined Cu/Cu2O and Ag nanoparticles on TiO2 for effective conversion of CO2 to CH4

High-performance photocatalysts for catalytic reduction of CO2 are largely impeded by inefficient charge separation and surface activity. Reasonable design and efficient collaboration of multiple active sites are important for attaining high reactivity and product selectivity. Herein, Cu-Cu2O and Ag nanoparticles are confined as dual sites for assisting CO2 photoreduction to CH4 on TiO2. The introduction of Cu-Cu2O leads to an all-solid-state Z-scheme heterostructure on the TiO2 surface, which achieves efficient electron transfer to Cu2O and adsorption and activation of CO2. The confined nanometallic Ag further enhances the carrier’s separation efficiency, promoting the conversion of activated CO2 molecules to •COOH and further conversion to CH4. Particularly, this strategy is highlighted on the TiO2 system for a photocatalytic reduction reaction of CO2 and H2O with a CH4 generation rate of 62.5 μmol∙g−1∙h−1 and an impressive selectivity of 97.49 %. This work provides new insights into developing robust catalysts through the artful design of synergistic catalytic sites for efficient photocatalytic CO2 conversion.